U.S. patent application number 17/261689 was filed with the patent office on 2021-09-09 for method for manufacturing graphene-metal composite wire.
The applicant listed for this patent is Nankai University. Invention is credited to Yongsheng Chen, Ai Ren, Tengfei Zhang.
Application Number | 20210276874 17/261689 |
Document ID | / |
Family ID | 1000005656345 |
Filed Date | 2021-09-09 |
United States Patent
Application |
20210276874 |
Kind Code |
A1 |
Chen; Yongsheng ; et
al. |
September 9, 2021 |
METHOD FOR MANUFACTURING GRAPHENE-METAL COMPOSITE WIRE
Abstract
The present disclosure provides a method for manufacturing a
graphene-metal composite wire. The method includes: (1) growing
graphene on a surface of a metal wire through a chemical vapor
deposition process; (2) twisting the wire; (3) pretensioning and
pre-straining the wire; (4) cold-drawing the wire; and (5)
subjecting the wire to a chemical vapor deposition process, wherein
the wire is subjected to steps (2) to (5) successively and cycled n
times, wherein f wires obtained in step (1) are used in the first
cycle, f wires obtained from previous cycle are used in subsequent
cycle, and finally a graphene-metal composite wire with fn strands
is obtained, and wherein (a) f is an integer of 2-9; and (b) n is
an integer of 6 or more.
Inventors: |
Chen; Yongsheng; (Tianjin,
CN) ; Zhang; Tengfei; (Tianjin, CN) ; Ren;
Ai; (Tianjin, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nankai University |
Tianjin |
|
CN |
|
|
Family ID: |
1000005656345 |
Appl. No.: |
17/261689 |
Filed: |
July 23, 2019 |
PCT Filed: |
July 23, 2019 |
PCT NO: |
PCT/CN2019/097285 |
371 Date: |
January 25, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C01B 2204/26 20130101;
C01B 2204/20 20130101; C23C 16/26 20130101; C01B 32/186 20170801;
C01P 2004/03 20130101; C23C 16/56 20130101; C01B 2204/24 20130101;
C01P 2002/82 20130101; H01B 1/04 20130101; C01B 2204/22
20130101 |
International
Class: |
C01B 32/186 20060101
C01B032/186; C23C 16/26 20060101 C23C016/26; C23C 16/56 20060101
C23C016/56; H01B 1/04 20060101 H01B001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 24, 2018 |
CN |
201810817130.2 |
Claims
1. A method for manufacturing a graphene-metal composite wire,
comprising the steps of: (1) growing graphene on a surface of a
metal wire through a chemical vapor deposition process; (2)
twisting the wire; (3) heat-treating the wire at 600-1100.degree.
C. for 30-60 minutes so that the wire becomes slack, then
subjecting the wire to a pre-tensioning operation immediately after
the heat treatment, and then cooling the wire to below 200.degree.
C. for a pre-straining operation; (4) cold-drawing the wire to
obtain a densified structure; and (5) subjecting the wire to a
chemical vapor deposition process, wherein the wire is subjected to
steps (2) to (5) successively and cycled n times, wherein f wires
obtained in step (1) are used in the first cycle, f wires obtained
from previous cycle are used in subsequent cycle, and finally a
graphene-metal composite wire with f.sup.n strands is obtained, and
wherein (a) f is an integer of 2-9; and (b) n is an integer of 6 or
more.
2. (canceled)
3. The method according to claim 1, wherein the method comprises an
optional step (3') between step (3) and step (4): subjecting the
wire to a chemical vapor deposition process so that graphene grows
on the surface thereof.
4. The method according to claim 1, wherein the chemical vapor
deposition process in step (1) is an atmospheric pressure chemical
vapor deposition process or a low-pressure chemical vapor
deposition process at a pressure of 1-300 Pa, in which a carrier
gas is selected from the group consisting of argon, helium,
hydrogen, and any combination thereof; a carbon source is a gaseous
carbon source or a liquid carbon source, the gaseous carbon source
is selected from the group consisting of methane, ethane, ethylene,
and any combination thereof, and the liquid carbon source is
selected from the group consisting of methanol, ethanol,
methylbenzene, and any combination thereof.
5. The method according to claim 1, wherein the chemical vapor
deposition process in step (1) comprises heat-treating the metal
wire by heating the metal wire to a temperature of 800-1100.degree.
C. and maintaining for 30-100 minutes; heating the metal wire to a
growth temperature that is in a range of 800-1100.degree. C. and
equal to or higher than the heat treatment temperature, and
contacting the metal wire with a carrier gas carrying a carbon
source, so that graphene grows on the surface of the metal wire for
5-60 minutes, wherein the carrier gas has a flow rate of 1-500
ml/min.
6. The method according to claim 1, wherein the chemical vapor
deposition process used in step (5) and the chemical vapor
deposition process used in the optional step (3') are the same as
the chemical vapor deposition process in step (1).
7. The method according to claim 1, wherein the twisting in step
(2) is carried out in an atmosphere of air, argon or helium, and a
twisting degree is 5-40 T/cm.
8. The method according to claim 1, wherein step (3) comprises
heat-treating the wire at 600-1100.degree. C. for 30-60 minutes so
that the wire becomes slack; subjecting the wire to a
pre-tensioning operation immediately after the heat treatment, then
cooling the wire to below 200.degree. C. for a pre-straining
operation; and repeating step (3) 3-8 times in a single cycle so
that an elongation of the wire is 10-30%.
9. The method according to claim 2, wherein step (4) comprises
subjecting the wire obtained in step (3) or (3') to cold drawing
with a cold drawing die at atmospheric pressure and room
temperature 1-30 times, wherein the wire is elongated by 2-5%
during each cold drawing, and a diameter of the wire finally
obtained in step (4) is the same as initial diameter of the metal
wire in step (1).
10. The method according to claim 1, wherein the metal wire is a
copper wire or a nickel wire.
11. The method according to claim 9, wherein the metal wire is a
red copper wire with a purity of 95-99.999% and a diameter of
0.05-0.5 mm.
12. The method according to claim 9, wherein the metal wire is a
commercial copper, and the metal wire is washed before step (1),
wherein the washing includes washing the metal wire with one or
more solvents selected from the group consisting of deionized
water, ethanol, acetone, isopropanol, and trichloromethane, and
repeating the washing 2-3 times.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a method for manufacturing
a graphene-metal composite wire, and specifically to a method for
manufacturing a graphene-metal composite wire that has a
multi-strand structure in which graphene is uniformly
distributed.
BACKGROUND
[0002] At present, the methods for manufacturing graphene mainly
refer to mechanical exfoliation process, redox process, chemical
vapor deposition (CVD) process, and the like. However, compared
with the first two processes, the chemical vapor deposition process
can obtain graphene with high quality and controllable layers
through catalysis with a specific metal substrate in the presence
of methane, acetylene, or the like as a carbon source. It is worth
noting that high-quality graphene may also grow on a
polycrystalline metal substrate, and the polycrystalline metal
substrate is cheaper than a monocrystalline metal substrate.
Therefore, the chemical vapor deposition process is one of the
efficient methods expected to be used for large-scale production of
high-quality graphene.
[0003] Because graphene has a series of excellent properties,
graphene-based composite materials can highly pertinently and
significantly improve the defects and disadvantages of the
materials. At present, when manufacturing a graphene-metal
composite material, introduced graphene is usually obtained by
mechanically exfoliating graphite or reducing oxidized graphene.
Such a graphene material is physically or chemically combined with
a metal powder or a metal precursor and then further processed to
obtain a graphene-metal composite material, but it is difficult to
completely solve the problem of dispersion uniformity and interface
phase separation of various components.
[0004] Manufacturing the graphene-metal composite material by
in-situ growth of graphene on the surface of metal particles using
the CVD process is an efficient means expected to solve the
dispersion problem and ensure interfacial bonding. However, the
greatest advantage of the metal substrate lies in production of a
large-area graphene film rather than small-size graphene. Further,
the metal particles are also very easy to sinter at a high
temperature and graphene cannot be uniformly formed on the surface
of the particles. At present, such CVD process neither guarantees
uniform distribution of graphene on zero-dimensional or
three-dimensional metal substrates, nor guarantees interfacial
interaction between graphene and metal.
[0005] In view of the above, the disclosure provides a method for
manufacturing a graphene-metal composite wire in order to solve
some existing problems.
SUMMARY
[0006] According to an aspect of the present disclosure, a method
for manufacturing a graphene-metal composite wire is provided. The
method includes: (1) growing graphene on a surface of a metal wire
through a chemical vapor deposition process; (2) twisting the wire;
(3) pre-tensioning and pre-straining the wire; (4) cold-drawing the
wire; and (5) subjecting the wire to a chemical vapor deposition
process, wherein the wire is subjected to steps (2) to (5)
successively and cycled n times, wherein f wires obtained in step
(1) are used in the first cycle, f wires obtained from previous
cycle are used in subsequent cycle, and finally a graphene-metal
composite wire with strands is obtained, and wherein (a) f is an
integer of 2-9; and (b) n is an integer of 6 or more. According to
another embodiment, the method includes: step (3') between step (3)
and step (4): subjecting the wire to a chemical vapor deposition
process so that graphene grows on the surface thereof.
[0007] According to an embodiment, the metal wire is washed before
step (1), and the washing includes washing the metal wire with one
or more solvents selected from the group consisting of deionized
water, ethanol, acetone, isopropanol, and trichloromethane, and
repeating the washing 2-3 times. According to another embodiment,
the chemical vapor deposition process in step (1) is an atmospheric
pressure chemical vapor deposition process or a low-pressure
chemical vapor deposition process at a pressure of 1-300 Pa, in
which a carrier gas is selected from the group consisting of argon,
helium, hydrogen, and any combination thereof; a carbon source is a
gaseous carbon source or a liquid carbon source, the gaseous carbon
source is selected from the group consisting of methane, ethane,
ethylene, and any combination thereof, and the liquid carbon source
is selected from the group consisting of methanol, ethanol,
methylbenzene, and any combination thereof.
[0008] According to an embodiment, the chemical vapor deposition
process in step (1) comprises heat-treating the metal wire by
heating the metal wire to a temperature of 800-1100.degree. C. and
maintaining for 30-100 minutes; heating the metal wire to a growth
temperature that is in a range of 800-1100.degree. C. and equal to
or higher than the heat treatment temperature, and contacting the
metal wire with a carrier gas carrying a carbon source, so that
graphene grows on the surface of the metal wire for 5-60 minutes,
wherein the carrier gas has a flow rate of 1-500 ml/min. According
to another embodiment, the chemical vapor deposition process used
in step (5) and the chemical vapor deposition process used in the
optional step (3') are the same as the chemical vapor deposition
process in step (1).
[0009] According to an embodiment, the twisting in step (2) is
carried out in an atmosphere of air, argon or helium, and a
twisting degree is 5-40 T/cm. According to another embodiment, step
(3) comprises heat-treating the wire at 600-1100.degree. C. for
30-60 minutes so that the wire becomes slack; subjecting the wire
to a pre-tensioning operation immediately after the heat treatment,
then cooling the wire to below 200.degree. C. for a pre-straining
operation. According to another embodiment, step (3) is repeated
3-8 times in a single cycle so that an elongation of the wire is
10-30%.
[0010] According to an embodiment, step (4) comprises subjecting
the wire obtained in step (3) or (3') to cold drawing with a cold
drawing die at atmospheric pressure and room temperature 1-30
times, wherein the wire is elongated by 2-5% during each cold
drawing. According to another embodiment, a diameter of the wire
finally obtained in step (4) is the same as initial diameter of the
metal wire in step (1).
[0011] According to an embodiment, the metal wire is a copper wire
or a nickel wire. According to another embodiment, the metal wire
is a red copper wire with a purity of 95-99.999% and a diameter of
0.05-0.5 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings are only used to illustrate one or
more embodiments of the present disclosure together with the
description, but are not intended to limit the scope of the present
disclosure.
[0013] FIG. 1 is a schematic structural diagram of a graphene-metal
composite wire with fn strands;
[0014] FIG. 2 is a Raman spectrum of graphene according to Example
1;
[0015] FIG. 3 is a SEM image of a wire obtained after twisting
according to Example 2;
[0016] FIG. 4 is a SEM image of the graphene-copper composite wire
obtained after cold drawing with a die according to Example 3;
[0017] FIG. 5 is an optical image of oxidation resistance of the
graphene-copper composite wire according to Example 4; and
[0018] FIG. 6 shows comparison of tensile strength of the
graphene-copper composite wire according to Example 7.
DETAILED DESCRIPTION
[0019] In order to better understand the contents of the present
disclosure, several specific embodiments are provided below. Those
skilled in the art will be able to modify the embodiments according
to actual situations, and may also combine the technical features
of different embodiments.
[0020] In an embodiment, a method for manufacturing a
graphene-metal composite wire is provided. The method includes: (1)
growing graphene on a surface of a metal wire through a chemical
vapor deposition process; (2) twisting the wire; (3) pretensioning
and pre-straining the wire; (4) cold-drawing the wire; and (5)
subjecting the wire to a chemical vapor deposition process, wherein
the wire is subjected to steps (2) to (5) successively and cycled n
times, wherein f wires obtained in step (1) are used in the first
cycle, f wires obtained from previous cycle are used in subsequent
cycle, and finally a graphene-metal composite wire with fn strands
is obtained, and wherein (a) f is an integer of 2-9; and (b) n is
an integer of 6 or more. In another embodiment, according to the
above step (1), a graphene-coated metal wire can be obtained
through in-situ growth of graphene with high coverage, high
quality, and controllable layers on the metal surface. In still
another embodiment, according to the above step (1), a
graphene-coated composite copper wire can be obtained with a
commercial red copper wire as a starting material.
[0021] The high coverage herein means that the coverage of graphene
on the metal surface is higher than 99%, preferably higher than
99.5%, 99.6%, 99.7%, 99.8%, or 99.9%. The number of graphene layers
on the metal surface herein is controlled to 1-10, e.g., 1, 2, 3,
4, 5, 6, 7, 8, 9, or 10.
[0022] In an embodiment, the chemical vapor deposition process in
step (1) is an atmospheric pressure chemical vapor deposition
process. In another embodiment, the chemical vapor deposition
process in step (1) is a low-pressure chemical vapor deposition
process, wherein the pressure is 1-300 Pa, e.g., 50, 100, 150, 200,
250 Pa.
[0023] In still another embodiment, in step (1), the carrier gas is
selected from the group consisting of argon, helium, hydrogen, and
any combination thereof, e.g., the carrier gas is a combined gas of
argon and hydrogen. In a further embodiment, in step (1), the
carbon source is a gaseous carbon source or a liquid carbon source,
the gaseous carbon source is selected from the group consisting of
methane, ethane, ethylene, and any combination thereof, and the
liquid carbon source is selected from the group consisting of
methanol, ethanol, methylbenzene, and any combination thereof.
Preferably, the gaseous carbon source, e.g., methane or ethane, is
used.
[0024] In an embodiment, the chemical vapor deposition process in
step (1) comprises heat-treating the metal wire by heating the
metal wire to a temperature of 800-1100.degree. C. and maintaining
for 30-100 minutes; heating the metal wire to a growth temperature
that is in a range of 800-1100.degree. C. and equal to or higher
than the heat treatment temperature, and contacting the metal wire
with a carrier gas carrying a carbon source, so that graphene grows
on the surface of the metal wire for 5-60 minutes, wherein the
carrier gas has a flow rate of 1-500 ml/min. In another embodiment,
the heat treatment temperature is 800, 850, 900, 950, 1000, or
1050.degree. C. In still another embodiment, the growth temperature
is 850, 900, 950, 1000, 1050, or 1100.degree. C. In an embodiment,
the growth duration of graphene is 5-60 minutes, preferably 10-40
minutes, e.g., 10, 15, 20, 25, 30, 35, or 40 minutes.
[0025] In an embodiment, the metal wire is washed before step (1),
and the washing includes washing the metal wire with one or more
solvents selected from the group consisting of deionized water,
ethanol, acetone, isopropanol, and trichloromethane, and repeating
the washing 2-3 times. In another embodiment, the metal wire is
washed with deionized water, ethanol, and acetone successively, and
the washing is repeated 2-3 times.
[0026] In an embodiment, the twisting in step (2) is carried out in
an atmosphere of air, argon, or helium, and a twisting degree is
5-40 T/cm, e.g., 5, 10, 15, 16, 20, 25, 30, 35, or 40 T/cm. In
another embodiment, in step (2), 2-9 graphene-coated wires may be
twisted, or 2-9 wires processed in previous cycle may be twisted.
for example, 2, 3, 4, 5, 6, 7, 8, or 9 wires are twisted. After
twisting, a part of graphene may be wrapped by other surrounding
metal wires, and after steps (3) and (4) described herein, graphene
may be distributed inside the composite wire.
[0027] In an embodiment, step (3) comprises heat-treating the wire
at 600-1100.degree. C. for 30-60 minutes so that the wire becomes
slack; subjecting the wire to a pre-tensioning operation
immediately after the heat treatment, then cooling the wire to
below 200.degree. C. for a pre-straining operation. In another
embodiment, the heat treatment temperature in step (3) is
600-1100.degree. C., 650-1050.degree. C., 700-1000.degree. C.,
750-950.degree. C., or 800-900.degree. C., and the heat treatment
duration is 30-60 minutes, 35-55 minutes, or 40-50 minutes. In
still another embodiment, step (3) may be repeated 3-8 times, e.g.,
3-5 times, so that an elongation of the wire is 10-30%, e.g., 10,
15, 18, 20, 25, or 30%. In another embodiment, when step (3) is
repeated, the same or different heat treatment temperatures may be
employed, and the same or different heat treatment durations may be
employed. A stress generated by twisting and stretching can be
eliminated in step (3) of the present disclosure, to achieve good
interfacial contact between metal wires and between the metal wire
and graphene, therefore the entire structure is densified, i.e.,
achieving the structure densification.
[0028] In an embodiment, an optional step (3') is arranged between
step (3) and step (4) as required, which comprises: subjecting a
wire obtained in previous step to a chemical vapor deposition
process so that graphene grows on the surface thereof. In another
embodiment, the chemical vapor deposition process used in step (3')
is the same as the chemical vapor deposition process in step (1).
In still another embodiment, the chemical vapor deposition process
used in step (3') is different from the chemical vapor deposition
process in step (1). In an embodiment, when cycle steps (2)-(5) are
repeated, step (3') may be optionally implemented, i.e., step (3')
may be implemented in each cycle, or step (3') may not be
implemented in each cycle, or step (3') may also be implemented as
required.
[0029] In an embodiment, step (4) comprises subjecting the wire
obtained in step (3) or (3') to cold drawing with a cold drawing
die at atmospheric pressure and temperature 1-30 times, wherein the
wire is elongated by 2-5% during each cold drawing. In another
embodiment, the diameter of the wire finally obtained in step (4)
is the same as the initial diameter of the metal wire in step (1),
i.e., obtaining a graphene-metal composite wire with the diameter
identical to the initial diameter of the metal wire, with an
increased length and with graphene uniformly distributed inside. In
still another embodiment, the cold drawing die is a diamond
high-precision drawing die with a round hole, and a drawing
lubricant may or may not be added during the drawing.
[0030] In an embodiment, the chemical vapor deposition process used
in step (5) is the same as the chemical vapor deposition process in
step (1). In another embodiment, the chemical vapor deposition
process used in step (5) is different from the chemical vapor
deposition process in step (1).
[0031] In an embodiment, the wire may be subjected to steps (2) to
(5) successively and cycled n times, where n is an integer of 6 or
more, for example, but not limited to, 6, 7, 8, 9, 10, 11, 12, 13,
14, 15, 16, 17, 18, 19 or 20. In another embodiment, f wires
obtained in step (1) are used in a first cycle, f wires obtained
from previous cycle are used in each subsequent cycle, and finally
a graphene-metal composite wire with to fn strands is obtained,
where f is an integer of 2-9, e.g., 2, 3, 4, 5, 6, 7, 8, or 9.
[0032] In an embodiment, the metal wire is a copper wire or a
nickel wire. In another embodiment, the metal wire is a red copper
wire with a purity of 95-99.999% and a diameter of 0.05-0.5 mm,
preferably a commercial red copper wire. In such embodiment, copper
is used as a substrate. Since copper hardly forms a solid solution
with carbon, copper mainly plays a catalytic role in the growth of
graphene. However, once graphene covers the surface of the copper
substrate, the catalytic effect of copper covered by graphene is
largely suppressed, thereby hindering the further deposition of
carbon atoms and the increase of the number of graphene layers.
Therefore, the method of the present disclosure can very
efficiently obtain a graphene film with a few of layers or even a
single layer by adjusting the process parameters.
[0033] The method according to present disclosure comprises in-situ
growth of graphene on the metal wire; then successively performing
twisting, pre-tensioning and pre-straining (densifying), and cold
drawing with a die; performing a plurality of cycles consisting of
the above steps, thereby finally obtaining a composite wire with
graphene uniformly distributed inside and with good interfacial
interaction between graphene and the metal substrate from a
microscopic perspective (see FIG. 1 for schematic structural
diagram thereof). The wire has excellent electrical and thermal
conducting properties, efficiently improved mechanical strength,
and excellent oxidation resistance and corrosion resistance. In
addition, continuous production can be realized using the method of
the present disclosure.
[0034] Further, according to the present disclosure, there is good
interfacial interaction between metal crystal grains and graphene
by in-situ growth of graphene, and several processing technologies
are combined and cycled many times, thereby effectively solving the
problem that graphene and metal materials are dispersed in the bulk
phase, and overcoming the defect that metal wires (e.g., copper
wires) cannot be used to prepare large-area and high-quality
graphene. Further, simple and continuous operations are used in the
method of the present disclosure, thereby facilitating the
implementation of large-scale production.
EXAMPLES
[0035] Embodiments of the present disclosure will be further
described below by providing examples. However, those skilled in
the art will understand that the provided examples are only used to
illustrate the present disclosure clearly, and are not intended to
limit the scope of the present disclosure in any way.
Example 1
[0036] (1) A commercial copper wire with a diameter of 0.1 mm and a
purity of 99% was washed with deionized water, ethanol, and acetone
successively, and the washing was repeated 3 times. An atmospheric
pressure chemical vapor deposition process was employed, argon and
hydrogen were used as carrier gas, the flow rate of the carrier gas
was 200 ml/min, ethane was used as carbon source, the heat
treatment temperature was 900.degree. C., and heat treatment was
performed for 30 minutes, the growth temperature was 950.degree.
C., and the growth duration was 20 minutes. Graphene with high
coverage, high quality and controllable layers continuously grew on
the surface of the copper wire to obtain a graphene-coated copper
wire with a controllable length (cf. FIG. 2).
[0037] (2) 3 samples were selected and twisted to obtain a twisted
wire. The twisting degree was 15 T/cm. This operation was performed
in air.
[0038] (3) The obtained twisted wire was heat-treated at
900.degree. C. for 40 minutes to make the twisted wire become
slack. The wire was stretched until it was straightened but
withstood a tension of less than or equal to 1 N to achieve
pre-tensioning, then was cooled to 180.degree. C. for a mechanical
pre-straining operation, and then was re-heated to 900.degree. C.
The above operations in step (3) were repeated 3 times, and finally
an elongation of the twisted wire was 15%.
[0039] (4) The obtained samples were subjected to the same
conditions and process as those in step (1), so that graphene grew
on the surface thereof again.
[0040] (5) The obtained samples were subjected to cold drawing with
a diamond high-precision drawing die at room temperature 15 times,
and finally a graphene-copper composite wire with the same diameter
as the initial copper wire was obtained.
[0041] (6) The obtained samples were subjected to the chemical
vapor deposition process again, so that graphene grew on the
surface thereof, wherein the process and conditions were the same
as those in step (1).
[0042] Further, steps (2)-(6) may be repeated successively for the
samples obtained in step (6), thereby realizing cyclic operations.
Specifically, a copper wire with a diameter of 0.1 mm was subjected
to step (1), then subjected to the above steps (2)-(6) and cycled 6
times, wherein 3 wires obtained in step (1) were selected for the
first cycle, and 3 wires obtained in step (6) of previous cycle
were selected for each of 5 subsequent cycles, thereby finally
obtaining a graphene-copper composite wire with 3.sup.6
strands.
Example 2
[0043] (1) A commercial copper wire with a diameter of 0.1 mm and a
purity of 99% was washed with deionized water, ethanol, and acetone
successively, and the washing was repeated 3 times. An atmospheric
pressure chemical vapor deposition process was employed, argon and
hydrogen were used as carrier gas, the flow rate of the carrier gas
was 300 ml/min, ethane was used as carbon source, the heat
treatment temperature was 900.degree. C., the heat treatment was
performed for 40 minutes, the growth temperature was 950.degree.
C., and the growth duration was 15 minutes. Graphene with high
coverage, high quality and controllable layers continuously grew on
the surface of the copper wire to obtain a copper wire fully coated
with graphene and with a controllable length.
[0044] (2) 4 samples were selected and twisted to obtain a twisted
wire. The twisting degree was 20 T/cm. This operation was performed
in air (cf. FIG. 3).
[0045] (3) The obtained twisted wire was heat-treated at
900.degree. C. for 40 minutes to make the twisted wire become
slack. The wire was stretched until it was straightened but
withstood a tension of less than or equal to 1 N to achieve
pre-tensioning, then was cooled to 120.degree. C. for a mechanical
pre-straining operation, and then was re-heated to 900.degree. C.
The above operations in step (3) were repeated 3 times, and finally
an elongation of the twisted wire was 15%.
[0046] (4) The obtained samples were subjected to the same
conditions and process as those in step (1), so that graphene grew
on the surface thereof again.
[0047] (5) The obtained samples were subjected to cold drawing with
a diamond high-precision drawing die at room temperature 15 times,
and finally a graphene-copper composite wire with the same diameter
as the initial copper wire was obtained.
[0048] (6) The obtained samples were subjected to the chemical
vapor deposition process again, so that graphene grew on the
surface thereof, wherein the process and conditions were the same
as those in step (1).
[0049] Further, steps (2)-(6) may be repeated successively for the
samples obtained in step (6), thereby realizing cyclic operations.
Specifically, a copper wire with a diameter of 0.1 mm was subjected
to step (1), then subjected to the above steps (2)-(6) and cycled 6
times, wherein 4 wires obtained in step (1) were selected for the
first cycle, and 4 wires obtained in step (6) of previous cycle
were selected for each of 5 subsequent cycles, thereby finally
obtaining a graphene-copper composite wire with 4.sup.6
strands.
Example 3
[0050] (1) A commercial copper wire with a diameter of 0.2 mm and a
purity of 99% was washed with deionized water, ethanol, and acetone
successively, and the washing was repeated 3 times. An atmospheric
pressure chemical vapor deposition process was employed, argon and
hydrogen were used as carrier gas, the flow rate of the carrier gas
was 250 ml/min, ethane was used as carbon source, the heat
treatment temperature was 900.degree. C., the heat treatment was
performed for 60 minutes, the growth temperature was 950.degree.
C., and the growth duration was 10 minutes. Graphene with high
coverage, high quality and controllable layers continuously grew on
the surface of the copper wire to obtain a copper wire fully coated
with graphene and with a controllable length.
[0051] (2) 3 samples were selected and twisted to obtain a twisted
wire. The twisting degree was 20 T/cm. This operation was performed
in air.
[0052] (3) The obtained twisted wire was heat-treated at
900.degree. C. for 40 minutes to make the twisted wire become
slack. The wire was stretched until the wire was straightened but
withstood a tension of less than or equal to 1 N to achieve
pre-tensioning, then was cooled to 150.degree. C. for a mechanical
pre-straining operation, and then was re-heated to 900.degree. C.
The above operations in step (3) were repeated 3 times, and finally
an elongation of the twisted wire was 18%.
[0053] (4) The obtained samples were subjected to cold drawing with
a diamond high-precision drawing die at room temperature 16 times,
and finally a graphene-copper composite wire with the same diameter
as the initial copper wire was obtained (cf. FIG. 4).
[0054] (5) The obtained samples were subjected to the chemical
vapor deposition process again, so that graphene grew on the
surface thereof, and the process and conditions were the same as
those in step (1).
[0055] Further, steps (2)-(5) may be repeated successively for the
samples obtained in step (5), thereby realizing cyclic operations.
Specifically, a copper wire with a diameter of 0.2 mm was subjected
to the above step (1), and then subjected to the above steps
(2)-(5) and cycled 8 times, wherein 3 wires obtained in step (1)
were selected for the first cycle, and 3 wires obtained in step (5)
of previous cycle were selected for each of 7 subsequent cycles,
thereby finally obtaining a graphene-copper composite wire with
3.sup.8 strands.
Example 4
[0056] (1) A commercial copper wire with a diameter of 0.2 mm and a
purity of 99% was washed with deionized water, ethanol, and acetone
successively, and the washing was repeated 3 times. An atmospheric
pressure chemical vapor deposition process was employed, argon and
hydrogen were used as carrier gas, the flow rate of the carrier gas
was 300 ml/min, methane was used as carbon source, the heat
treatment temperature was 900.degree. C., heat treatment was
performed for 40 minutes, the growth temperature was 950.degree.
C., and the growth duration was 20 minutes. Graphene with high
coverage, high quality and controllable layers continuously grew on
the surface of the copper wire to obtain a copper wire fully coated
with graphene and with a controllable length.
[0057] (2) 6 samples were selected and twisted to obtain a twisted
wire. The twisting degree was 15 T/cm. This operation was performed
in air.
[0058] (3) The obtained twisted wire was heat-treated at
800.degree. C. for 40 minutes to make the twisted wire become
slack. The wire was stretched until the wire was straightened but
withstood a tension of less than or equal to 1 N to achieve
pre-tensioning, then was cooled to 100.degree. C. for a mechanical
pre-straining operation, and then was re-heated to 800.degree. C.
The above operations in step (3) were repeated 3 times, and finally
an elongation of the twisted wire was 18%.
[0059] (4) The obtained samples were subjected to the same
conditions and process as those in step (1), and graphene grew on
the surface thereof again.
[0060] (5) The obtained samples were subjected to cold drawing with
a diamond high-precision drawing die at room temperature 15 times,
and finally a graphene-copper composite wire with the same diameter
as the initial copper wire was obtained.
[0061] (6) The obtained samples were subjected to the chemical
vapor deposition process again, so that graphene grew on the
surface thereof, wherein the process and conditions were the same
as those in step (1).
[0062] Further, steps (2)-(6) may be repeated successively for the
samples obtained in step (6), thereby realizing cyclic operations.
Specifically, a copper wire with a diameter of 0.2 mm was subjected
to step (1), and then subjected to the above steps (2)-(6) and
cycled 8 times, where 6 wires obtained in step (1) were selected
for the first cycle, and 6 wires obtained in step (6) of previous
cycle were selected for each of 7 subsequent cycles, thereby
finally obtaining a graphene-copper composite wire with 6.sup.8
strands.
[0063] The graphene-copper composite wire has excellent oxidation
resistance. In detail, after being heated to 200.degree. C. for 5
minutes in an air environment, the graphene-copper composite wire
was observed that only a small number of positions on the surface
were oxidized, while blank control samples (i.e., copper wires
without graphene) were completely oxidized on the surface (see FIG.
5 for comparison results).
Example 5
[0064] (1) A commercial copper wire with a diameter of 0.3 mm and a
purity of 99.9% was washed with deionized water, ethanol, and
acetone successively, and the washing was repeated 3 times. An
atmospheric pressure chemical vapor deposition process was
employed, argon and hydrogen were used as carrier gas, the flow
rate of the carrier gas was 300 ml/min, methane was used as carbon
source, the heat treatment temperature was 900.degree. C., the heat
treatment was performed for 30 minutes, the growth temperature was
1000.degree. C., and the growth duration was 20 minutes. Graphene
with high coverage, high quality and controllable layers
continuously grew on the surface of the copper wire to obtain a
copper wire fully coated with graphene and with a controllable
length.
[0065] (2) 4 samples were selected and twisted to obtain a twisted
wire. The twisting degree was 20 T/cm. This operation was performed
in air.
[0066] (3) The obtained twisted wire was heat-treated at
900.degree. C. for 40 minutes to make the twisted wire become
slack. The wire was stretched until the wire was straightened but
withstood a tension of less than or equal to 1 N to achieve
pre-tensioning, then was cooled to 150.degree. C. for a mechanical
pre-straining operation, and then was re-heated to 900.degree. C.
The above operations in step (3) were repeated 3 times, and finally
an elongation of the twisted wire was 18%.
[0067] (4) The obtained samples were subjected to the same
conditions and process as those in step (1), and graphene grew on
the surface thereof again.
[0068] (5) The samples obtained in step (4) were subjected to cold
drawing with a diamond high-precision drawing die at room
temperature 15 times, and finally a graphene-copper composite wire
with the same diameter as the initial copper wire was obtained.
[0069] (6) The obtained samples were subjected to the chemical
vapor deposition process again, so that graphene grew on the
surface thereof, wherein the process and conditions were the same
as those in step (1).
[0070] Further, steps (2)-(6) may be repeated successively for the
samples obtained in step (6), thereby realizing cyclic operations.
Specifically, a copper wire with a diameter of 0.3 mm was subjected
to step (1), and then subjected to the above steps (2)-(6) and
cycled 6 times, wherein 4 wires obtained in step (1) were selected
for the first cycle, and 4 wires obtained in step (6) of previous
cycle were selected for each of 5 subsequent cycles, thereby
finally obtaining a graphene-copper composite wire with 4.sup.6
strands.
Example 6
[0071] (1) A commercial copper wire with a diameter of 0.3 mm and a
purity of 99.9% was washed with deionized water, ethanol, and
acetone successively, and the washing was repeated 3 times. An
atmospheric pressure chemical vapor deposition process was
employed, argon and hydrogen were used as carrier gas, the flow
rate of the carrier gas was 350 ml/min, methane was used as carbon
source, the heat treatment temperature was 900.degree. C., the heat
treatment was performed for 40 minutes, the growth temperature was
1050.degree. C., and the growth duration was 10 minutes. Graphene
with high coverage, high quality and controllable layers
continuously grew on the surface of the copper wire to obtain a
copper wire fully coated with graphene and with a controllable
length.
[0072] (2) 8 samples were selected and twisted to obtain a twisted
wire. The twisting degree was 16 T/cm. This operation was performed
in argon.
[0073] (3) The obtained twisted wire was heat-treated at
1000.degree. C. for 40 minutes to make the twisted wire become
slack. The wire was stretched until the wire was straightened but
withstood a tension of less than or equal to 1 N to achieve
pre-tensioning, then was cooled to 150.degree. C. for a mechanical
pre-straining operation, and then was re-heated to 1000.degree. C.
The above operations in step (3) were repeated 5 times, and finally
an elongation of the twisted wire was 20%.
[0074] (4) The obtained samples were subjected to the same
conditions and process as those in step (1), and graphene grew on
the surface thereof again.
[0075] (5) The obtained samples were subjected to cold drawing with
a diamond high-precision drawing die at room temperature 20 times,
and finally a graphene-copper composite wire with the same diameter
as the initial copper wire was obtained.
[0076] (6) The obtained samples were subjected to the chemical
vapor deposition process again, so that graphene grew on the
surface thereof, wherein the process and conditions were the same
as those in step (1).
[0077] Further, steps (2)-(6) may be repeated successively for the
samples obtained in step (6), thereby realizing cyclic operations.
Specifically, a copper wire with a diameter of 0.3 mm was subjected
to step (1), and then subjected to the above steps (2)-(6) and
cycled 6 times, where 8 wires obtained in step (1) were selected
for the first cycle, and 8 wires obtained in step (6) of previous
cycle were selected for each of 5 subsequent cycles, thereby
finally obtaining a graphene-copper composite wire with 8.sup.6
strands.
Example 7
[0078] (1) A commercial copper wire with a diameter of 0.5 mm and a
purity of 99.9% was washed with deionized water, ethanol, and
acetone successively, and the washing was repeated 3 times. An
atmospheric pressure chemical vapor deposition process was
employed, argon and hydrogen were used as carrier gas, the flow
rate of the carrier gas was 300 ml/min, ethylene was used as carbon
source, the heat treatment temperature was 900.degree. C., heat
treatment was performed for 35 minutes, the growth temperature was
1000.degree. C., and the growth duration was 15 minutes. Graphene
with high coverage, high quality and controllable layers
continuously grew on the surface of the copper wire to obtain a
copper wire fully coated with graphene and with a controllable
length.
[0079] (2) 4 samples were selected and twisted to obtain a twisted
wire. The twisting degree was 20 T/cm. This operation was performed
in argon.
[0080] (3) The obtained twisted wire was heat-treated at
1050.degree. C. for 40 minutes to make the twisted wire become
slack. The wire was stretched until the wire was straightened but
withstood a tension of less than or equal to 1 N to achieve
pre-tensioning, then was cooled to 160.degree. C. for a mechanical
pre-straining operation, and then was re-heated to 1050.degree. C.
The above operations in step (3) were repeated 3 times, and finally
an elongation of the twisted wire was 18%.
[0081] (4) The obtained samples were subjected to the same
conditions and process as those in step (1), and graphene grew on
the surface thereof again.
[0082] (5) The obtained samples were subjected to cold drawing with
a diamond high-precision drawing die at room temperature 20 times,
and finally a graphene-copper composite wire with the same diameter
as the initial copper wire was obtained.
[0083] (6) The obtained samples were subjected to the chemical
vapor deposition process again, so that graphene grew on the
surface thereof, and the process and conditions were the same as
those in step (1).
[0084] Further, steps (2)-(6) may be repeated successively for the
samples obtained in step (6), thereby realizing cyclic operations.
Specifically, a copper wire with a diameter of 0.5 mm was subjected
to step (1), and then subjected to the above steps (2)-(6) and
cycled 6 times, where 4 wires obtained in step (1) were selected
for the first cycle, and 4 wires obtained in step (6) of previous
cycle were selected for each of 5 subsequent cycles, thereby
finally obtaining a graphene-copper composite wire with 4.sup.6
strands.
[0085] The composite copper wire was tested for tensile performance
with an electronic universal tensile tester, and its tensile
strength was improved to greater than 200 MPa, as shown in FIG.
6.
[0086] Those skilled in the art can understand that appropriate
modification and changes may be made to the embodiments of the
present disclosure, without departing from the spirit or scope of
the present disclosure. The scope of the present disclosure is
intended to be determined by the appended claims and equivalents
thereof.
* * * * *